Correlation between sonography and antibody activity in patients with Hashimoto thyroiditis

Patients with Hashimoto thyroiditis show structural changes of the thyroid that can be identified by a variety of sonographic criteria. We conducted this study to investigate whether there is a correlation between sonography and antibody activity and to assess the role of sonography in the diagnosis and follow-up of Hashimoto thyroiditis. In addition, we present a new classification system (termed the VESINC system [volume, echogenicity, sonographic texture, pseudonodular hypoechoic infiltration, nodules, and cysts]), which helps improve the clarity of sonographic findings.

The study included 223 consecutive patients with previously diagnosed Hashimoto autoimmune thyroiditis who attended the thyroid clinic of the German Armed Forces Central Hospital in Koblenz for follow-up examinations between 2006 and 2008. Laboratory tests were performed to measure the levels of free triiodothyronine, free thyroxine, thyrotropin, anti-thyroglobulin antibodies (TgAbs), and antithyroid peroxidase antibodies (TPOAbs). Sonography was performed according to a strict protocol. We then assessed whether a correlation existed between antibody activity and the 6 sonographic variables of the VESINC system.

Hypoechogenicity, heterogeneity, and pseudonodular hypoechoic infiltration were associated with significantly higher TPOAb activity (P < .001). There were no significant correlations between the other sonographic variables examined (cysts, nodules, and volume) or the biometric data with the TPOAb and TgAb levels. In addition, an assessment of TgAb levels did not show significant differences in correlations with any of the sonographic variables.

Sonography is a noninvasive diagnostic imaging modality that provides information about the level of inflammatory activity. Markedly decreased echogenicity, heterogeneity, and multifocal pseudoinodular hypoechoic infiltration are indicative of a high level of inflammatory activity. The sonographic classification system presented here (VESINC system) can be a useful tool for comparing sonographic findings in a rapid and objective manner during follow-up of Hashimoto thyroiditis.